 
				
		
		
				About six weeks ago, after an extended development cycle, AMD launched their latest flagship ATI-GPU based graphics card, the Radeon HD 2900 XT.  The Radeon HD 2900 XT is built around the company's unified, DirectX 10-class, R600 GPU and offers a number of key features over an above the older X1000 series of products, like new anti-aliasing modes and support for shader model 4.0.
		
		
				At the time of the HD 2900 XT's debut, AMD also disclosed a multitude of details regarding mobile and mainstream GPUs derived from the R600 architecture.  In our coverage of the Radeon HD 2000 series as it became known, we talked about not only the Radeon HD 2900 XT, but five other members of the family, including the Radeon HD 2600 XT (GDDR3 and GDDR4 versions), the 2600 Pro, and the Radeon HD 2400 XT and Pro.  Unfortunately, cards weren’t ready in time to launch alongside the 2900 XT, but they are now and we’ve got a trio of them in house for a benchmarking throw-down.
		
		
				On the pages ahead, we’ll go into detail on the new Radeon HD 2600 XT GDDR4, the Radeon HD 2600 Pro, and the Radeon HD 2400 XT, and compare their performance to a number of current and previous generation cards.  But first, here are the Radeon HD 2600 and HD 2400 series’ features and specifications, as per the folks at ATI...
		
		
				
				
		
		
				
						
								|   | 
												
														
																| ATI Radeon HD 2600 Family |  
																| Features and Specifications |  | 
				
		
		
				
						
						
				
		
		
				
						
								
										| 
														
																
																		390 million transistors on 65nm fabrication process 
																
																
																		128-bit DDR2/GDDR3/GDDR4 memory interface 
																
																
																		Ring Bus Memory Controller 
																
																
																		Unified Superscalar Shader Architecture 
																 
																		
																				
																						120 stream processing units 
																				 
																						
																								
																										Dynamic load balancing and resource allocation for vertex, geometry, and pixel shaders 
																								
																								
																										Common instruction set and texture unit access supported for all types of shaders 
																								
																								
																										Dedicated branch execution units and texture address processors 
																								
																				
																						128-bit floating point precision for all operations 
																				
																				
																						Command processor for reduced CPU overhead 
																				
																				
																						Shader instruction and constant caches 
																				
																				
																						Up to 40 texture fetches per clock cycle 
																				
																				
																						Up to 128 textures per pixel 
																				
																				
																						Fully associative multi-level texture cache design 
																				
																				
																						DXTC and 3Dc+ texture compression 
																				
																				
																						High resolution texture support (up to 8192 x 8192) 
																				
																				
																						Fully associative texture Z/stencil cache designs 
																				
																				
																						Double-sided hierarchical Z/stencil buffer 
																				
																				
																						Early Z test, Re-Z, Z Range optimization, and Fast Z Clear 
																				
																				
																						Lossless Z & stencil compression (up to 128:1) 
																				
																				
																						Lossless color compression (up to 8:1) 
																				
																				
																						8 render targets (MRTs) with anti-aliasing support 
																				
																				
																						Physics processing support 
																				
																
																		Full support for Microsoft® DirectX 10.0 
																
																
																		Dynamic Geometry Acceleration 
																 
																		
																				
																						High performance vertex cache 
																				
																				
																						Programmable tessellation unit 
																				
																				
																						Accelerated geometry shader path for geometry amplification 
																				
																				
																						Memory read/write cache for improved stream output performance 
																				
																
																		Anti-aliasing features 
																 
																		
																				
																						Multi-sample anti-aliasing (up to 8 samples per pixel) 
																				
																				
																						Up to 24x Custom Filter Anti-Aliasing (CFAA) for improved quality 
																				
																				
																						Adaptive super-sampling and multi-sampling 
																				
																				
																						Temporal anti-aliasing 
																				
																				
																						Gamma correct 
																				
																				
																						Super AA (CrossFire configurations only) 
																				
																				
																						All anti-aliasing features compatible with HDR rendering 
																				 | 
														
																
																		
																				Texture filtering features 
																		 
																				
																						
																								2x/4x/8x/16x high quality adaptive anisotropic filtering modes (up to 128 taps per pixel) 
																						
																						
																								128-bit floating point HDR texture filtering 
																						
																						
																								Bicubic filtering 
																						
																						
																								sRGB filtering (gamma/degamma) 
																						
																						
																								Percentage Closer Filtering (PCF) 
																						
																						
																								Depth & stencil texture (DST) format support 
																						
																						
																								Shared exponent HDR (RGBE 9:9:9:5) texture format support 
																						
																		
																				CrossFire Multi-GPU Technology 
																		 
																				
																						
																								Acale up rendering performance and image quality with 2 or more GPUs 
																						
																						
																								Integrated compositing engine 
																						
																						
																								High performance dual channel interconnect 
																						
																		
																				ATI Avivo HD Video and Display Platform 
																		 
																				
																						
																								Dedicated unified video decoder (UVD) for H.264/AVC and VC-1 video formats 
																						
																						
																								Hardware MPEG-1, MPEG-2, MPEG-4/DivX video decode acceleration 
																						
																						
																								Avivo Video Post Processor 
																						
																						
																								High Quality Video Post Processing 
																						 
																								
																										
																												Advanced vector adaptive per-pixel de-interlacing 
																										
																										
																												De-blocking and noise reduction filtering 
																										
																										
																												Detail enhancement 
																										
																										
																												Inverse telecine (2:2 and 3:2) 
																										
																										
																												Bad edit correction 
																										
																						
																								Two independent display controllers 
																						 
																								
																										
																												Drive two displays simultaneously with independent resolutions, refresh rates, color controls and video overlays for each display 
																										
																										
																												Full 30-bit display processing 
																										
																										
																												Programmable piecewise linear gamma correction, color correction, and color space conversion 
																										
																										
																												Spatial/temporal dithering provides 30-bit color quality on 24-bit and 18-bit displays 
																										
																										
																												High quality pre- and post-scaling engines, with underscan support for all display outputs 
																										
																										
																												Content-adaptive de-flicker filtering for interlaced displays 
																										
																										
																												Fast, glitch-free mode switching 
																										
																										
																												Hardware cursor 
																										
																						
																								Two integrated dual-link DVI display outputs 
																						 
																								
																										
																												Each supports 18-, 24-, and 30-bit digital displays at resolutions up to 2560x1600 
																										
																										
																												Each includes a dual-link HDCP encoder with on-chip key storage for high resolution playback of protected content 
																										
																						
																								Two integrated 400 MHz 30-bit RAMDACs 
																						
																						
																								HDMI output support 
																						 
																								
																										
																												Supports resolutions up to 1920x1080 
																										
																										
																												Integrated HD audio controller with multi-channel (5.1) AC3 support, enabling a plug-and-play cable-less audio solution 
																										
																						
																								Integrated AMD Xilleon HDTV encoder 
																						 
																								
																										
																												Provides high quality analog TV output (component/S-video/composite) 
																										
																										
																												Supports SDTV and HDTV resolutions 
																										
																										
																												Underscan and overscan compensation 
																										
																						
																								MPEG-2, MPEG-4, DivX, WMV9, VC-1, and H.264/AVC encoding and transcoding 
																						
																						
																								Seamless integration of pixel shaders with video in real time 
																						
																						
																								VGA mode support on all display outputs 
																						
																						
																								PCI Express x16 bus interface 
																						
																						
																								OpenGL 2.0 support
																						 | 
						
				
		 
		
				
						
								|   | 
												
														
																| ATI Radeon HD 2400 Family |  
																| Features and Specifications |  | 
				
		
		
				
						
								
								
						
				
		
		
				
						
								
										| 
														
																
																		
																				180 million transistors on 65nm fabrication process 
																		
																		
																				64-bit DDR2/GDDR3 memory interface 
																		
																		
																				Unified Superscalar Shader Architecture 
																		 
																				
																						
																								40 stream processing units 
																						 
																								
																										
																												Dynamic load balancing and resource allocation for vertex, geometry, and pixel shaders 
																										
																										
																												Common instruction set and texture unit access supported for all types of shaders 
																										
																										
																												Dedicated branch execution units and texture address processors 
																										
																						
																								128-bit floating point precision for all operations 
																						
																						
																								Command processor for reduced CPU overhead 
																						
																						
																								Shader instruction and constant caches 
																						
																						
																								Up to 16 texture fetches per clock cycle 
																						
																						
																								Up to 128 textures per pixel 
																						
																						
																								Fully associative vertex/texture cache design 
																						
																						
																								DXTC and 3Dc+ texture compression 
																						
																						
																								High resolution texture support (up to 8192 x 8192) 
																						
																						
																								Fully associative texture & Z/stencil cache designs 
																						
																						
																								Early Z test, Re-Z, Z Range optimization, and Fast Z Clear 
																						
																						
																								Lossless Z & stencil compression 
																						
																						
																								8 render targets (MRTs) with anti-aliasing support 
																						
																						
																								Physics processing support 
																						
																		
																				Full support for Microsoft DirectX 10 
																		
																		
																				Dynamic Geometry Acceleration 
																		 
																				
																						
																								Programmable tessellation unit 
																						
																						
																								Accelerated geometry shader path for geometry amplification 
																						
																						
																								Memory read/write cache for improved stream output performance 
																						
																		
																				Anti-aliasing features 
																		 
																				
																						
																								Multi-sample anti-aliasing (up to 4 samples per pixel) 
																						
																						
																								Custom Filter Anti-Aliasing (CFAA) for improved quality 
																						
																						
																								Adaptive super-sampling and multi-sampling 
																						
																						
																								Temporal anti-aliasing 
																						
																						
																								Gamma correct 
																						
																						
																								Super AA (CrossFire configurations only) 
																						
																						
																								All anti-aliasing features compatible with HDR rendering 
																						
																		
																				Texture filtering features 
																		 
																				
																						
																								2x/4x/8x/16x high quality adaptive anisotropic filtering modes (up to 128 taps per pixel) 
																						
																						
																								128-bit floating point HDR texture filtering 
																						
																						
																								Bicubic filtering 
																						
																						
																								sRGB filtering (gamma/degamma) 
																						
																						
																								Percentage Closer Filtering (PCF) 
																						
																						
																								Depth & stencil texture (DST) format support 
																						
																						
																								Shared exponent HDR (RGBE 9:9:9:5) texture format support 
																						 
														
														  |  | 
						
				
		 
		
		
				There is some pertinent information related to today's launch available on our site that we recommend you read, to get familiar with ATI's R600 GPU, their previous GPU architectures, and their key features. The Radeon HD 2600 XT, 2600 Pro, and 2400 XT are derivatives of the R600, and such they have a number of key features in common that we've already covered in much greater detail. The article we suggest you peruse include:
		
		
		
				If you haven't already done so, we recommend scanning through our 2900 XT / R600 coverage, our CrossFire Multi-GPU technology preview, the Radeon X1950 Pro with Native CrossFire article, and the X1K family review. In those four pieces, we cover a large number of the features offered by the new Radeon HD 2600 / 2400 series and explain many of benefits of DirectX 10. We recommended reading these articles because there is quite a bit of background information in them that'll lay the foundation for what we're going to showcase here today.